KappaCCD

• Introduction
• Safety instructions Read these before using the equipment
• Specifications
• Installation
• Pre-installation requirements
• Operation
• Maintenance and repairs
• Troubleshooting
• Manufacturer and Service

Introduction
 

The KappaCCD consists of a X-ray source, three axes goniometer (Omega, Kappa, Phi) to position the crystal and a Theta axis and DX to position the detector. The two-dimensional detector measures the X-ray, which is reflected in the crystal.

The X-ray can be generated by a fixed tube as part of the goniometer and a HV generator or by a stand alone rotating anode generator. The X-ray optics consists of a main shutter, a fast shutter, a monochromator to suppress the ß- and brehms radiation and a collimator to get a small bundle. Safety switches close the main shutter or switch off the high voltage in unsafe conditions. In case of a rotating anode the main shutter and some safeties are handled by the generator. A microscope displays the crystal on the PC monitor. In the two-dimensional detector a phosphor converts the X-ray to light, a fibre optic taper reduces the image and a cooled scientific grade CCD measures the light signal.

The axes are decoded by precision optical encoders and are driven by DC motors, which permit accurate, fast and smooth positioning with low power. The system is controlled by a Server computer. A Host computer with data collecting and evaluating software connects to the system. The goniometer is surrounded by a radiation enclosure, which prevents access to the radiation and suppresses scattered X-ray.
 
 

• X-ray
• Beryllium

X-ray safety

The equipment generates open X-ray, which can cause human hazards when safety rules are not followed:

• The equipment must be operated under the responsibility of an X-ray safety officer, as stated by local regulations.
• The equipment must be operated, serviced and maintained by qualified personnel who are trained with the hazards of and precaution against X-ray exposure.
• The equipment contains safety circuits which should not be overridden, other than supplied: the enclosure key and beamstop override vane. These overrides may only be used for service and maintenance, i.e. X-ray alignment.
• The enclosure key and beamstop override vane should not be kept with the instrument but under the custody of the X-ray safety officer. This also applies to the X-ray- or shutter safety keys of the X-ray generator in case the X-ray port is not used or X-ray is not allowed to be used.
• When using the beamstop override vane (only for alignment) the system must not be left unattended. Theta always at 0°, safety door closed, low kV/mA setting and a second lead beamstop.
• The radiation enclosure is equipped with a second beamstop. It must not be removed and the goniometer primary beam must be pointed to this beamstop.
• Safety circuits must be tested by service personnel or the safety officer at least every 12 months, as described in this manual (chapter Maintenance).
• The collimator must always be installed.

The detector and X-ray tube contain windows of beryllium. In normal use these area's cannot be reached, but during maintenance, care must be taken not to touch the window. When by accident the beryllium is touched, wash with soap and water.

Fumes and dust from beryllium metal can be hazardous if inhaled. During use, corrosion of the beryllium window may occur, but it should not be cut, machined or otherwise removed. Tube and detector disposal must comply with the national and local regulations governing beryllium.
 
 

 

Goniometer

Anti collision

• Automatic anti-collision software.
• Axis maximum position switches. Turning back is possible.
• Collision switches on detector, collimator holder and beamstop.

X-ray optics

 

Detector

Image defects (which are compensated for in software)

• 'Warm' pixels. A certain percentage of the pixels will have a higher dark current than average.
• Zingers. Spurious high intensity spots or stripes. These are mostly caused by muons, generated by cosmic radiation, which traverse the silicon of the CCD.
• Distortion of the image. This is very low, caused by the taper.
• Non uniform sensitivity, mostly caused by taper properties, such as separations between fibre bundles (chicken wires).
• A maximum of two black columns (grade 1).

Safety interlocks

The shutter does not open, or is closed when:

• The collimator is not in the right position.
• The monochromator or X-ray port is not in the right position.
• The beamstop is not mounted.
• The shutter open lamps are defect.
• The radiation enclosure is not closed.
• When using a rotating anode: the goniometer is not properly placed in front of the X-ray port.

• The shutter does not close.
• The high voltage cable is not connected to the X-ray tube (indicated by a link, attached to the cable and connected to the tube holder).
• The X-ray on lamp is defect.

The system is supplied with two overrides, which are only allowed to be used during technical maintenance (see safety rules).

• A key switch overrides the radiation enclosure safety. This state is signalled by the flashing Open beam lamp. When the lamp is defect the override is cancelled.
• Beamstop override vane. There are no extra warnings. See X-ray safety.

With a X-ray generator all safeties are handled by the generator, except the shutter safeties: collimator and beam stop.

Safety signals

• Shutter open lamp: illuminated when the shutter is opened or is not fully closed.
• Shutter closed lamp (only with sealed tube): illuminated when the shutter is fully closed.
• Open beam lamp: flashes when the radiation enclosure safety is overridden.
• X-ray lamp: illuminated when X-rays are generated.

Safety with power off

Safety demands that circuits are automatically in a safe position when they are out of order. So during power off, the goniometer Interface and the X-ray high voltage are switched off by the safeties.

 

Environmental, according to IEC 1010

 

General

Position

• The equipment must be installed in a normal, clean and temperature regulated environment and not in direct sunlight.
• The primary beam must be pointed to the second beamstop in the radiation enclosure.

• The power voltage is factory installed (see identification label on the Interface) and can only be changed by a service engineer.
• UPS. For the CCD electronics and liquid cooler an uninterruptable power supply is recommended to prevent the CCD temperature to rise fast in case of a power failure. For a long lifetime a slow temperature gradient is advised. The power connection is:
• 
• When the power is off, the CCD Controller is powered off, signalling the power unit to slowly rise the temperature till it reaches the 0 ºC of the liquid cooler. When the power returns before the UPS battery is empty, the temperature will slowly return to -60 ºC. When power returns after the UPS is empty, the liquid cooler will not restart automatically and the CCD will not cool down.

 

• The cooler should be filled with cooling liquid till half the indicating glass (in the past it was custom to fill it till the maximum of the glass)
• For a Julabo cooler, adjust to autostart after power up :
• Press the key menu
• Select with horizontal arrow :  St
• Adjust with vertical arrow : 0
• Press enter and then menu key

Electronic interfaces are mounted in the cabinet or placed on the table top. They must not be placed within 50 cm of the X-ray tube, to prevent electrical problems due to spilt cooling water. Ventilation holes must not be covered and no insulating or heavy object must be placed on the equipment.

Safety ground

• The equipment must be connected to the installation safety ground, e.g. through a appropriate power cable.
• The next safety ground must be checked: from the HV generator to the X-ray tube.

A detector - crystal distance of 25 mm (using an ECON goniometer head) is possible when a modified beamstop is used. Take care the cooling head is not in the way of any goniometer movement.
 

Positioning the system as shown in the figures. In this position the angle between the vertical axis and the cooling head is about 10 degrees. For DX = 25 mm a modified beamstop must be used. Note that the dummy cooling head has a smaller diameter and is therefore not well suited for sorting out the proper position. It is possible to place a cuff around the dummy to make it suitable.

External Phi limit switch for use with the FR559 crystal heating device

• Preparing for installation . -----------------------------
• You will need a (Windows 95/98) version of the KappaCCD server program, dated after 26 March 1999 (go to the help in the main server window to see this date).
• You will need a interface software version dated after 26 March 1999. This date is printed on an E-prom at the left side of the CPU printed circuit board in the goniometer interface (there are two printed circuit boards in the goniometer interface; the CPU board is the one with only one connector at the front)
• There are a series of settings that must be modified in the server program set-up, some related to the phi limit switch unit, some to the special goniometer head you will be using. It is therefore probably best to copy your original settings file for re-use once you are finished using your limit-switch unit. The set-up file is called KCCD.SET and is located in C:\CCD\SERVER.
• Mounting the limit switch unit.
• Remove the black disk at the back of the Kappa block (there is a screw at the centre of the block)
• Remove the dripping tray at the base of the kappa support block.
• Position phi to 0 degrees
• Mount the switch unit using the support bracket and 2 screws. The switch unit should be mounted at the right side of the phi axis :
• 
• Now the disks supplied must be mounted on the phi axis; the largest first (phi should be at 0 degrees during this operation).
• There is a cam in the smallest disk that fits a slit in the largest disk.
• There is a Allen screw at the side of the smallest disk that can be loosened during mounting.
• It is important to position both disks correctly; the cam on the small disk should be positioned close to the small vane that can be seen under the switch unit (the vane has 2 micro-switches that sense the left and right movement of the vane).
• Because of the cam and slit this implies the protruding part of the biggest disk will be positioned at the opposite side.
• Once both disks are positioned and fixed to the phi axis the Allen screw can be tightened.
• In the server program go to setup->goniometer setup-> goniometer constants and enable "phi limit switch unit".
• Set the geometry of the goniometer head you will be using in setup->goniometer head setup. For the 558 heating device set the top angle to 90 degrees and the maximum radius to 30 (mm).
• Shut down the server program.
• Some additional settings in the C:\CCD\SERVER\KCCD.SET set-up file have to be modified; these can be done using a regular text editor such as notepad or edit (in case you are using a dos window). Look for the following parameters and modify their contents as follows :
• GON_PHI_MIN = -240
• GON_PHI_MAX = 240
• GON_DX_MIN = 45
• GON_COLLISION_SECURITY = 3
• PHI_MIN and PHI_MAX are phi axis limitations because of the limit switch unit.
• DX_MIN is the minimum distance that can be considered safe because of the protruding parts of the heating device. If your goniometer head has a different geometry, you might want to use a different value. If that case you can start the server program using the standard value (in most cases GON_DX_MIN=25) and position phi and DX (while keeping kappa = 0 ) until you find the proper value. NOTE : the several motors of the goniometer are quite strong and can do a lot of damage to the detector and/or goniometer alignment if a crash occurs outside of the regular collision collars.
• GON_COLLISION_SECURITY is the clearance in degrees the software keeps between the kappa block and the detector/collimator/beamstop. The same remarks as for DX_MIN apply here.
• Fix the plug of the switch unit to the socket marked "Limit switch" at the back of the goniometer. During standard use a dummy plug is used in this socket; it must be re-applied after removing the limit switch unit.
• Restart the server program.
• Enough slack should be kept for the several cables running between the limit switch unit and the phi axis device and the outside world, also when moving omega and kappa. If the device tends to "strangle" itself it is possible to limit the kappa range : modify in KCCD.SET the GON_KAPPA_MIN and GON_KAPPA_MAX to appropriate values if necessary (default is -175 and 175 respectively).

Goniometer

Goniometer Interface

Detector

Red status led on the  Power unit: (in the first series the status led can be on another position)
 

Off	Cooling off or fault condition.
On	Cooling switch on (after approx. 30 s) and cooling liquid at approx. 0°C or lower.
1/4 on, 3/4 off	Cooling switch off and CCD above approx. +10°C, ready to switch off the power (or cooling liquid too warm to start cooling).
3/4 on, 1/4 off	Cooling switch off and cooling liquid below approx. +10°C: ready to start cooling or: Cooling switch on and cooling liquid above approx. +10°C: cooling liquid too warm.

Green led on the Power unit: power on of both Controller and power unit. For test of only the power unit: check with the controller powered off.

• Start-up
• Shut-off
• Server software

• Switch on the Goniometer interface, Detector Power unit and controller but with the cooling switch on front of the detector controller off. (When the systems were already on: first switch off, then on)

• Switch on the liquid cooler to a temperature of 0°C.
• After the cooler has reached this temperature, adjust the CCD temperature on the Controller to -60°C (60 on the dial, not in the small window: less than one turn). Never adjust lower than -60°C. (the red lamp on front of the black Power unit should flash 3/4 on 1/4 of, when 1/4 on 3/4 off the liquid temperature is too high, when off the Power unit is in error).
• Switch on the cooling switch on the Controller. (the red lamp on front of the black Power unit goes on continuous, when off the Power unit is in error).
• Cooling down can take approx. 1.5 hr. The temperature is reached when the green lamp near the temperature adjustment lights.
• Start the Server program on the Server computer. The goniometer will first look for the zero position (operation: GONINIT). When finished (operation: none) the system is ready to get mastership from the Host computer (mastership: none). It is also possible to work with the server program after setting the mastership local with the command Acquisition · Grab mastership.

Detector cooling off:

• Switch the cooling switch on the Controller off.  After about an hour adjust the liquid cooler to +20°C. The temperature is now slowly raised by the power unit, to prevent a temperature shock. A fast warming up, for instance during power failure will not damage the CCD, but for a long lifetime a slow gradient is advised. Wait till the led on the Power unit switches 1/4 on, 3/4 off (after approx. 1.5 hour) before switching off the Controller and Power unit.

Host computer

Server computer

• Commands for technical service.
• Input of goniometer and detector parameters.
• Actions which are required near the goniometer, like aligning the crystal.
• Possibility to run a measurement.
• Bitmap utility to display measured images.
• Program to display the image of the microscope.
• Log window and file to save technical messages and diagnostic output.

Calibration files and set-up file

With a ; (semicolon) placed before GONIOMETER_PRESENT the server program starts up without the goniometer. This can be used to test the detector. The calibration files are saved in C:\CCD\CALIBR
 

GRID.KCD (or .SPE)	Image with holes on a 0.032" raster to calculate the image distortion compensation.
NUNF...KCD	Images from a Yttrium sample to calculate the non uniform sensitivity. An image without X-ray is made (background) and two images with X-ray at 2Theta = +45° and -45°.

The file C:\CCD\CALIBR\INFOLOG.TXT contains some calibration data, installation data and other log remarks.

Upgrading Server software

• Cleaning
• Tools
• Safety test
• X-ray optics alignment
• with a sealed tube (FR590)
• Effic: intensity of the primary beam
• Revacuum
• Reset
• Microscope alignment
• Repair small shutter
• Ceramic tubes
• Uninterruptable Power Supply
• Replaceable parts

For cleaning use a damp cloth, moistened with water or isopropyl alcohol. No cleaning agent may enter the goniometer.

• Absorber: Zirconium (for Mo) or Nickel (for Cu) filter, placed on the collimator to attenuate the intensity of the primary beam to a measurable and save level. It is only allowed to used with low kV/mA settings. Specification:
• Mo: 7 foils of 0.108 mm Zr, attenuation approx. 2400x
• Cu: 9 foils of 0.02 mm Ni, attenuation approx. 1900x
• Half-beam absorber: a 2 mm bar, placed in the crystal head.
• Test crystal: ammonium bitartrate.

Shutter safety, with the FR590 or FR591.

1. Switch off the X-ray high voltage
2. Open the shutter with Acquisition · Toggle shutter. Check both shutter-open lamps.
3. Check if the shutter will not open after activating the next unsafe conditions. The shutter must remain closed after reestablishment of the safety (except the shutter lamps):
• Collimator loose.
• Beamstop removed.
• Radiation enclosure open.
• Shutter-open lamps removed.
• Radiation enclosure safety override with the key-switch, Beam-open lamp removed and enclosure open.
4. Check the flashing Open-beam lamp when the radiation enclosure safety is override by the key-switch.

1. Switch on the high voltage to minimum: 20 kV 5 mA
2. Check the X-ray on lamps.
3. Check if the high voltage falls off when:
• X-ray on lamps removed.
• Link of the HV connector removed.
• Main shutter is manually opened by hand: take care not to come in the vicinity of the primary beam!

1. Switch on the high voltage on minimum: 20 kV 5 mA.
2. Check if the high voltage falls off when:
• Shutter is manually opened by hand: take care not to come in the vicinity of the primary beam!
3. See safety tests in FR591 service manual.

Safety precautions

1. Don't let other persons come in the neighbourhood of the system.
2. Don't leave the system unattended, before reestablishment of the safety.
3. Don't come in the primary beam, although for security reasons it is attenuated to a weak and safe intensity.

Measurement set-up

1. Zero all axes (this means Omega is 160°). DX = 150 mm. Always keep Theta = 0°. No beta filter.
2. Place a #353 collimator.
3. Place the absorber on the collimator (take care: Mo and Cu use different absorbers).
4. Remove the beamstop and place the red vane (safety switch override). take care, the primary beam is measured, be sure the second beamstop (X-ray shield) in the radiation enclosure is in place (the PVC windows are not sufficient to stop the primary beam), see X-ray safety instructions.
5. X-ray generator:
• Mo: 30 kV, 10 mA
• Cu: 20 kV, 10 mA
6. For measurements use in the server : Setup · Calibrate · Beam-alignment.

Adjustment

1. Adjust Tube 2Theta to 0°.
2. Dismount the monochromator and mount the X-ray port (two Allen screws {2.5 mm} at the bottom, which can be reached by two holes {not the middle one} under the black monochromator holder). During replacement the power of the X-ray generator must be off.
3. Adjust tube 2Theta = 0° and take-off = 3.0° (for fine focus 0.4 x 8 mm).
4. Adjust on approx. maximum intensity with tube vertical (Allen 4.0 mm) and tube horizontal (Allen 3.0 mm) adjustment (measurement Continuous).
5. Raise the generator mA till the intensity is approx. 10000 ADU.
6. Mount the half-beam absorber (3 mm bar) on a goniometer head. Align it with the microscope with / (former view 1) and Phi 90° rotated: the edge of the bar must be in the centre (it must absorb half of the beam).
7. Align horizontal and vertical :
• Start a measurement (horizontal or vertical). Two measurements are executed with Phi 180° rotated.
• Both measurements must be equal within 5%. If not : adjust with tube horizontal or vertical adjustment to the proposed "new" value (with measurement Continuous) and measure again.
• Lock the tube vertical adjustment (Allen 5.0 mm).
8. Test the alignment of the half-beam absorber :
• Remove the half-beam absorber and measure Open.
• Place the half-beam absorber and measure Vane. The error should be not more than 25%. If it is : adjust to the advised new value and measure again. When the alignment was bad, check the previous tube alignment again.
9. Remove the half-beam absorber and X-ray port. Switch off the power of the X-ray generator during replacement.
10. Mount the monochromator and switch on the power of the X-ray generator.
11. Adjust Tube 2Theta (Mo: 12.2°, Cu: 26.6°) and the Monochromator Theta on the anode target material used.
12. Adjust the intensity on maximum. First with monochromator Theta, then tube 2Theta and monochromator height.
13. Lock the monochromator height.
14. Measure the open intensity.
15. Mount the half-beam absorber and position horizontal with "Vertical" (don't use the result of this measurement). Measure continuously and adjust with monochromator theta till the intensity is half the previous measured open intensity ±10% (a first coarse alignment).
16. As before, adjust the intensity within 5%:
• Vertical : with monochromator theta (with measurement vertical)
• Horizontal : with tube horizontal (with measurement horizontal).
17. Lock the monochromator Theta.
18. Set the X-ray generator to 10 mA and measure the open intensity (measurement Open) without the half-beam absorber. This is the Effic value.

Adjustment points

The effic measurement is a relative measurement of the intensity of the primary beam, which measures the total efficiency of the X-ray: tube, optics and detector gain. When the value is too low it is mostly caused by the tube (degradation) or the X-ray alignment. The measurement is done during installation of the system and later measurements can be compared with this value. Take into account that because of tolerance in collimator and absorber (material thickness) the values cannot be accurately compared with other systems.

Measurement:

• Measurement set-up: see X-ray alignment
• Measure the intensity op the open beam in the Server program with Setup·Calibrate·Beam-alignment with measurement Open.
• With new sealed tubes, fine focus, this value should be approx.:

	Mo	Cu
with monochromator	3000 cps	5500 cps
without monochromator (no beta filter)	5000 cps	9500 cps

After some time the vacuum of the detector can become lower, resulting in not reaching the low temperature (minimal after one year, mostly after several years). The quality of the detector or measurements will not be influenced by a lower vacuum. The vacuum can easily be restored with a standard vacuum pump and the tube set delivered with the system:

1. Shut off the detector.
2. Connect a vacuum pump to the vacuum connection on top of the detector (an oil filter is not necessary).
3. Switch on the vacuum pump till it reaches approx. 4 Pa (30 mTorr, 0.04 mbar).
4. Open the vacuum valve at the side of the detector (two full turns).
5. Wait till the pressure is at least the above value.
6. Close the vacuum valve with a torque of 3.5 - 4.0 Nm (approx. 30 Lbf-inches) switch off the vacuum pump.

When the goniometer program halts, it can be reset by the button on the front of the interface. A reset is also possible by switching off the power but this will also switch off the X-ray high voltage.

Fine adjustment of the microscope is done  with two screws at the back plate of the holder.

This repair can only be done by an mechanical engineer and only when advised by the Service department

• Part 1
• Mount the steel ball, centre it and centre the microscope.
• Remove the microscope including its square holder from the beamstop holder with two screws (don't remove it from the holder).
• Remove the black shutter cover (with the yellow led).
• You will see now the shutter coil and plunger. Remove the plunger and clean it with acetone. Clean the hole of the coil with a filt tip  with acetone.
• Place the plunger and test with shutter open/close if it works all right. When it does, go to part 3
• Part 2. This part is done when a new shutter and alignment bar is send from the Service department.
• Remove the steel ball including the crystal head (is later used as a reference for the microscope alignment)
• Loosen Allen screw A and remove the shutter assembly.
• 
• Unscrew the coil and screw it on the new shutter.
• Place the new shutter in such a way that the X-ray channel is in the direction of the beam path and the locking screw (which must not be touched) is opposite to the mounting screw A.
• Place the alignment bar in place of the collimator with the small tip (which fits in the shutter hole)  to the shutter. Do not tighten the collimator locking screw too much, so the alignment bar can slide.
• Align the shutter assembly in such a way that the alignment bar fits inside the X-ray channel and tighten Allen screw A.
• The alignment tool must be returned to the Service department.
• Part 3
• Mount all items again.
• Align the microscope on the steel ball.
• The old shutter parts must be returned to the Service department.

The batteries of the UPS have a life time of at least 3-4 years at 20º C and a few power downs per year (at higher temperatures like 30 ºC it can be half this time). After this time is it advised to switch off the power (on the power rail inside the cabinet at  the backside) and check if the liquid cooler still runs after 1 hour and at least 2 indicating LED's are on. Then switch on the system. If the time becomes too short, the battery should be replaced.

X-ray tube replacement

• See FR590 manual, chapter 4.2.2: Draining.
• The tube holder is designed for an A-version (short) tube. When using a B version (long) tube the 13 mm adapter must be used.
• If the removed tube is used again : first measure the Effic for later reference.
• Realign the X-ray optics.
• Maintenance of the tube: See FR590 manual, chapter 5.3: X-ray tube.

Monochromator

1. First switch off the power of the X-ray generator.
2. The monochromator is fixed with screws from below the collimator stand.
3. First adjust the Tube 2Theta before mounting.
4. With the X-ray port: first adjust Tube 2Theta before mounting.
5. When not mounted in the right position the shutter will not open.
6. After changing: realign the X-ray optics.

Collimator

Beamstop

Replaceable parts

Fuses

Lamp

• 24 V, 50 mA, 1,2 W, BA9s. Long life type. part number 2603.335 (order in lots of 10). It is not allowed to install a Led lamp, because a defect lamp is not detected by the Safety interlocks.

O-ring seals

• Between X-ray tube and tube holder: part number 2132.017.
• Water hose connection: part number 2132.018.

Test crystal

• The status of the goniometer can be checked in the server program with: SETUP • Goniometer • Diagnostic
• Start-up and communication problems
• Detector check failure 6,256, ADC error or 'Specified AD Converter not installed'
• No acquisition possible / CCD not present
• Zero finding
• Collision and maximum angle switch
• Temperature problem CCD or cooler
• Leakage of cooling liquid
• Error in the image
• Generator down (software message)
• X-ray intensity problem
• Main shutter does not open
• Crystal centring with liquid nitrogen
• Communication problem with the FR591 generator
• Problems with liquid cooler or Uninterruptable Power Supply

Start-up and communication problems

• PC-server program remains in: present operation = Goninit
• Kappa does not move and Omega is slowly running to its maximum position: check the dummy plug on the goniometer connector 'Limit switch'. Before replacing first switch off/on the Interface.
• Detector check failure 6,256, ADC error or 'Specified AD Converter not installed'
• Check the cable between PC board and controller, especially the connectors
• Check if the PC  board is good positioned in its connector. This can be critical. Remount the board.
• Add the line SKIP_ZERO at the top of start-up file C:\CCD\SERVER\KCCD.SET with notepad.  (take care to remove this line after testing !)
• Reset the interface. After start of the server program:
• Program does not ask: "Do you want to skip zero?":
• Check again with power off/on (the reset button does perhaps not work). If still not asking then there is probably a RS232 communication problem. Proceed:
• Check +5V power supply When you feel confident to check the electronics: open the Interface box from top and measure the +5V on the test pins on the back board with the power indicating LED's. It should not be lower than 4.8V. If it is not::
• Disconnect and connect the front connector on the power supply: the upper one on the right.
• If this does not help, probably the power supply is defect.
• Check the two LED's on the Interface Processor board. Both must be off, the left one blinks. After power-up the processor starts to autobaud: sends messages with different baudrate to the computer  with shows as blinking of the left led (Send, every 5 s). The computer answers (right led, Receive), after which the communication is established (both fast blinking for a short time).
• Present operation = none (system has started) : It is a problem in the goniometer.
• Read the diagnostics in Service program: Goniometer, diagnostics. Check "Omega limit switch reached" which should be 0. If it is 1 please consult the Service department.
• Update the position in the service program. Take care: it takes his present position as zero and anti-collision software does not work.
• Position every axis +/- 5 degree and check which axis does not position right.
• Check in SETUP • Goniometer • Diagnostic if there are Positioning or Index errors and inform the service department.
• No communication with the goniometer: PC-server program is not executing GONZERO but directly goes to NONE:
• Check in server program: Setup, Goniometer, if the goniometer is present (tagged). If not: edit the file \kccd\server\kccd.set and add a line GONIOMETER_PRESENT (tagging in the setup does not help because of a software bug)
• Host computer
• Message: "Could not make connection:need mastership to cryostat".
• Check the settings in the Server program: Setup, Network, Automasterset to Network should be tagged.
• Software bug. Use the newest server software upgrade

If after grabbing mastership the acquisition image in de Server program, remains grey:

• Check in Setup if CCD is present.
• If not, force CCD present and then read the CCD parameters: if the frequency is blank (it should give 200 kHz) then the PC cannot connect to the detector controller. Check:

• Is the power of the ST138 on.
• Check the thin cable between PC and detector controller. Remove and reconnect the connectors.
• Be sure the cable is connected to the TAXI board, because sometimes it is by accident connected to a COM port.
• Open the PC and remove/replace the TAXI board to be sure it is right positioned.
• Check in Windows if the Taxi board is installed: My computer, Control panel, System, Device manager, Data Acquisition, Princeton Instruments PCI Interface, General.
• Some eccentric errors:
• Defect PC memory

The anti-collision software prevents the goniometer from colliding with the collimator holders or the axis to run past their limits. When a collision takes place because of unexpected circumstances, like a technical error, it is sometimes possible to return:

1. On the Server computer a menu appears.
2. Choose the axis and direction to run out of collision.
3. Press the overrule button at the back of the goniometer. The axis now positions a small step.
4. If not enough: repeat. As soon as the collision switch is released, the goniometer starts to relocate the zero position.

• Continuously detector collision:  Remove the black collision ring (with an easy click) and dry and clean it inside. This error especially occurs with using a cryostat, which can cause condensation in the ring. Check the position

• First check the temperature of the cooling liquid (approx. 0 °C). If this is not OK:
• Check if there is enough ventilation.
• Warm up the detector and switch off. If the liquid temperature is still too high, the error is in the liquid cooler.
• Start up again.
• Rotate the temperature adjustment on the CCD controller till the led is green: this is the real CCD temperature.
• If it is slightly higher then -60 then probably the detector need to be revacuumed. For the moment it is possible to work for instance at -55. Most detectors has a very low dark current which, because of the automatic background compensation, will not influence the quality of the measurement at higher temperatures.
• If the temperature is very high, the cooling could be switched off.
• Switch off the ST138 and check if the green front led of the black power unit is on. If not:
• Check the fuse at the back of the power unit. If this is right of blows again after replacement, then inform the service department
• Switch the power unit off and on and check the red front led, which should remain on. If it switches off, please check the error on the right side of the Power unit. Through a slit three of four LED's are visible (not with some of the first series). With four LED's normally the most left one is on (is the same as the front red led) and the one next to it flashes. In case of error the three right ones give an error code. Please note which is on and off and consult our service  department.
• 

• Small leakage at the coolers site: Although the cooling bath is closed, condensation is possible at high humidity (must higher than our ambient specification). When the cooler was filled till its maximum, spill over will occur. Be sure to fill the cooler in the right way, so you can check when it is full. Take into account the liquid should not be diluted too much with water, otherwise it will freeze.
• High leakage can occur in older equipment, at the connection of the flexible tubes (to detector or cooler) to the metal tube (in the radiation enclosure. For fast (or temporary) repair, open it and try to reconnect. The Service department can send you clamps for this. The connection of the detector tubes are at the position where the tubes enters the roof.

• Light area in the right part of the image when measured with high Theta : this is X-ray background scattered from the beamstop (only several ADU).
• Image broken in blocks. The image is wrong written in PC memory.
• Check the connectors of the cable between CCD controller and the PC.
• Check if the PC board of the CCD controller is fitted in the PC in the right way.
• Run a performance  measurement in Setup·CCDsetup·CCDtestsuite. It is a test without X-rays.
• The ADC-zero will be between 50 - 150 with 200 kHz. Other values have no influence on the measurement, unless it is lower than 10.
• The readout noise is typical less than 2.5 with 200 kHz.
• The dark current is typical less than 10 with the 600 s measurement. The dark current is so low, that even a higher value will have a minor influence on the measurement quality.
• Check a flood field measurement with the Yttrium sample.
• Use a 353 collimator. Position Theta = +22.5° and Phi = +45°. The sample should be parallel to the detector surface. Measure for at least 10 minutes. take care, the radiation is high in all directions. It must be measured with a closed X-ray enclosure
• Mo: Yttrium sample, 50 kV 40 mA.
• Cu: Fe sample, 45 kV 32 mA.

Generator down (software message)

The X-ray high voltage is off. The generator will show the cause. Possible reasons in the goniometer are:

• The shutter does not close (also indicated by the shutter lamp). When this happens the shutter must be repaired.
• The high voltage cable is not connected to the X-ray tube. This is indicated by a link, attached to the cable and connected to the X-ray on lamp.
• The X-ray on lamp is defect.

• No X-ray (but no error messages):
• Check if there is also no X-ray with the Effic measurement.
• If the main shutter opens (audible and visible) and the led on the small shutter is on, then probably this shutter should be cleaned of replaced.
• X-ray too low:
• After mounting a new (Siemens) tube: check if the tube is right. It should have a part number ending with -180 and not -90 (which gives a line focus).
• Check the Effic measurement and compare it with earlier measurements. Mostly a low intensity is caused by the X-ray tube. When you want to be sure the error is not in the detector you can check the intensity of the primary beam with a separate detector (for instance a scintillator detector usable for 8-18 keV).
• Check the realignment of the goniometer. Perhaps the primary beam doesn't go through the centre of the goniometer. It is also possible to test it by using a small 0.4 mm steel ball on the crystal position and make an image of the primary beam (Always with absorber and low HV/mA setting)

Crystal centring with liquid nitrogen

To prevent changing of the crystal centre when using liquid nitrogen:

• Use a metal crystal head.
• Use the brass mounting pin
• In collect: use the low temperature limitation. If not:
• The glass capillary maximum 5 mm.

Problems with liquid cooler or Uninterruptable Power Supply

If the equipment is out of warranty the repair can be carried out by the local representative. The addresses can be found on the web:

• For Lauda cooler: http://www.lauda.de/
• For Julabo cooler: http://www.julabo.de/jgmbh/english/vertriebspartner.asp
• For Best Power UPS: http://www.powerware.com

BRUKER AXS B.V., P.O. Box 811, 2600 AV Delft, The Netherlands, Tel: 31 15 2152400 Fax: 31 15 2152500.

Service: see our web site: www.bruker-AXS.com